Three new antioxidant furofuran lignans from Callicarpa nudiflora

Three new lignans, (1R, 2R, 5R, 6R)-1-hydroxy-2-(3,4-methylenedioxyphenyl)-6-(3,4-dihydroxyphenyl)-3,7-dioxabicyclo[3.3.0] octane (1), (1R, 2S, 5R, 6R)-1-hydroxy-2-(3,4-methylenedioxyphenyl)-6-(3,4-dihydroxyphenyl)-3,7-dioxabicyclo[3.3.0] octane (2), and (1R, 2S, 5R, 6R)-1-hydroxy-2-(3,4-dihydroxyphenyl)-6-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3.3.0] octane (3), were isolated from the leaves of Callicarpa nudiflora Hook. Their structures were elucidated on the basis of spectroscopic data and chemical methods. Compounds 1-3 exhibited antioxidant activities with EC50 values of 19.8, 18.5, and 8.3 mu M, respectively. (C) 2013 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.